Voids can cause concrete to crack, which can lead to trip hazards and injuries, so you’ll want to fill them in right away. But, how can you detect voids beneath your concrete?
There are a few methods to detect voids under a concrete slab, including ground penetrating radar (GPR). Below, we explore what GPR is, its limits and applications, and why it’s a useful tool in repairing concrete voids.
HOW DOES GROUND PENETRATING RADAR WORK?
According to Global GPR Services, “GPR uses a high frequency radio signal that is transmitted into the ground and reflected signals are returned to the receiving and stored on digital media. The computer measures the time taken for a pulse to travel to and from the target which indicates its depth and location. The reflected signals are interpreted by the system and displayed on the unit's LCD panel.”
To put it simply, GPR emits a pulse into the ground and records the resulting echoes. This allows you to detect what is or isn’t underneath the ground.
HOW DEEP CAN GROUND PENETRATING RADAR GO?
GRP can reach depths of up to 100 feet (30 meters) in materials such as sand or granite, according to U.S. Radar Inc. Due to the density of concrete, though, the depth of GPR decreases to 3 feet (1 meter) or less.
WHAT IS GROUND PENETRATING RADAR USED FOR?
GPR has the same basic principles as a metal detector, but it’s abilities as a noninvasive method of assessing what’s below the surface go beyond looking for gold. By emitting a pulse into the ground and recording the resulting echoes, GPR can be used to locate objects in the ground, ranging from bodies to pipelines to metal objects.
Similarly, GPR can also be used to identify voids in the ground, as it will have a different composition than the surrounding material. Mr. Level, for example, uses GPR as a nondestructive solution to assess concrete and concrete structures for slab thickness and voids.
(Pro Tip: Homeowners can quickly and easily assess the strength of your concrete by dribbling a basketball on the concrete. If you hear an echo or feel like the ground is shaking, then there is likely a void.)
FILL VOIDS WITH MR. LEVEL
Mr. Level uses polyurethane to stabilize soil and fill voids under concrete by drilling a small, dime-sized hole into the concrete to inject the foam. The polyurethane then expands to fill the voids and hardens within 15 seconds for a quick cure time.
Need a concrete assessment or void filled? Contact Mr. Level today to get a free quote.